From Creatures Wikia
The smell lobe is one of the lobes in the brain. It registers if things smell in the creature's vicinity, and how strongly they smell.
The neurons are as follows:
Self Hand Door Seed Plant Weed Leaf Flower Fruit Manky Detritus Food Button Bug Pest Critter Beast Nest Animal Egg Weather Bad Toy Incubator Dispenser Tool Potion Elevator Teleporter Machinery Creature Egg Norn Home Grendel Home Ettin Home Gadget Portal Vehicle Norn Grendel Ettin Something